We already have test_helper with some helper methods but it would be great to also add various RSpec matchers so that matching on Sentry events is easy and concise.

Rough API sketch:

expect(sentry_events).to include_sentry_event("Ooops")
  .with_exception(RuntimeError, "Gaah!")
  .with_context("rails.error" => {some: "stuff"})
  .with_tags(%w[foo bar])